hsx/hotspot-gc/hotspot: 8009536: G1: Apache Lucene hang during reference processing

[Bengt Rutisson]

Uwe,

Thanks for verifying the fix! You really provided an excellent bug report.

John,

Great that you got this fixed so quickly! I like that you added the 
Lucene test to your testing portfolio. Is there any way we can add it to 
the common testing? I'm guessing that we don't have a lot of tests that 
stress the marking overflow handling since we didn't catch this in our 
internal testing. Are there any license issues with including the Lucene 
test in our nightly testing?

Thanks,
Bengt

On 4/2/13 10:48 PM, John Cuthbertson wrote:
> Hi Uwe,
>
> Thanks for the update. That is good to know. The bulk of the credit 
> goes to Bengt who did the initial diagnosis and the prototype fix.
>
> Thanks also for walking me through how to reproduce the issue. Once 
> the magic formula for the proxy was found - your instructions were 
> spot on. The tests were awesome as marking stress tests and uncovered 
> several issues associated with concurrent marking overflows. I've 
> added them to the set of tests I run for marking changes. :)
>
> Cheers,
>
> JohnC
>
> On 4/2/2013 12:16 PM, Uwe Schindler wrote:
>> Hi John,
>>
>> today I installed JDK8 b83 on one of the Jenkins build servers used 
>> by Apache Lucene: The problem with 32 bit JVMs and G1 collector is 
>> solved. I compared the trunk checkout of Lucene with both JVMs: In 
>> b82 it hangs, in b83 it passes. So I was able to re-enable 32 bit 
>> builds without the extra workaround stacksize option again.
>>
>> Thanks for fixing this issue.
>>
>> Uwe
>>
>> -----
>> Uwe Schindler
>> uschindler at apache.org
>> Apache Lucene PMC Member / Committer
>> Bremen, Germany
>> http://lucene.apache.org/
>>
>>> -----Original Message-----
>>> From: hotspot-gc-dev-bounces at openjdk.java.net [mailto:hotspot-gc-dev-
>>> bounces at openjdk.java.net] On Behalf Of john.cuthbertson at oracle.com
>>> Sent: Tuesday, March 19, 2013 2:21 AM
>>> To: hotspot-gc-dev at openjdk.java.net
>>> Subject: hg: hsx/hotspot-gc/hotspot: 8009536: G1: Apache Lucene hang
>>> during reference processing
>>>
>>> Changeset: fa08949fe0cb
>>> Author:    johnc
>>> Date:      2013-03-18 11:05 -0700
>>> URL:       http://hg.openjdk.java.net/hsx/hotspot-
>>> gc/hotspot/rev/fa08949fe0cb
>>>
>>> 8009536: G1: Apache Lucene hang during reference processing
>>> Summary: In CMTask::do_marking_step(), Skip offering termination and
>>> entering the first and second synchronization barriers if called 
>>> from a serial
>>> context, i.e. the VM thread.
>>> Reviewed-by: brutisso, tschatzl
>>>
>>> ! src/share/vm/gc_implementation/g1/concurrentMark.cpp
>>> ! src/share/vm/gc_implementation/g1/concurrentMark.hpp
>